A predictive mechanical model for evaluating vertebral fracture probability in lumbar spine under different osteoporotic drug therapies

Abstract

Osteoporotic vertebral fractures represent a major cause of disability, loss of quality of life and even mortality among the elderly population. Decisions on drug therapy are based on the assessment of risk factors for fracture from bone mineral density (BMD) measurements. A previously developed model, based on the Damage and Fracture Mechanics, was applied for the evaluation of the mechanical magnitudes involved in the fracture process from clinical BMD measurements. BMD evolution in untreated patients and in patients with seven different treatments was analyzed from clinical studies in order to compare the variation in the risk of fracture. The predictive model was applied in a finite element simulation of the whole lumbar spine, obtaining detailed maps of damage and fracture probability, identifying high-risk local zones at vertebral body. For every vertebra, strontium ranelate exhibits the highest decrease, whereas minimum decrease is achieved with oral ibandronate. All the treatments manifest similar trends for every vertebra. Conversely, for the natural BMD evolution, as bone stiffness decreases, the mechanical damage and fracture probability show a significant increase (as it occurs in the natural history of BMD). Vertebral walls and external areas of vertebral end plates are the zones at greatest risk, in coincidence with the typical locations of osteoporotic fractures, characterized by a vertebral crushing due to the collapse of vertebral walls. This methodology could be applied for an individual patient, in order to obtain the trends corresponding to different treatments, in identifying at-risk individuals in early stages of osteoporosis and might be helpful for treatment decisions.

Finite element analysis of dynamic changes in spinal mechanics of osteoporotic lumbar fracture

“…At present, osteoporotic fracture is considered to be an important public health problem that not only increases morbidity and mortality in the elderly, but also incurs important economic costs. In addition, osteoporotic lumbar fracture often causes spinal cord injury, which is the main cause of disability, reduced quality of life, and even death in the elderly [ 1 ]. Thoracolumbar vertebra refers to T 11 –L 2 , which is a special segment of the spine.…”

“…Osteoporosis is one of the common basic diseases in the elderly with calcium loss in the body and bone mass reduction which is more prone to cause fracture and occur in the thoracolumbar vertebrae [ 1 , 2 ]. Osteoporosis is a systemic skeletal disease, the occurrence and development of which is the result of the comprehensive action of many systems, such as nerve, endocrine, immunity, reproduction, musculoskeletal, and so on.…”

A 3D finite element model of prophylactic vertebroplasty in the metastatic spine: Vertebral stability and stress distribution on adjacent vertebrae

“…Therefore, we decided to study the lumbar spine segment, as recently evaluated in a predictive mechanical model for evaluating vertebral fracture probability in lumbar spine under different osteoporotic drug therapies. 32 In future studies, we are planning to study localization of metastasis to the thoracic spine. Finally, our study did not consider metastases on multiple levels.…”

Analysis of medical images to support decision-making in the musculoskeletal field

“…Thus, osteoporosis is a major public health issue, which slowly evolves as an asymptomatic condition, with increasing probabilities of developing fragility fractures (MCCLUNG, 2005;LÓPEZ et al, 2016). Studies have shown that a previous spine fracture increases the risk of future hip fracture, which in turn is associated with increased morbidity and mortality in elderly people (TELLACHE et al, 2009;HAMMERNIK et al, 2015).…”

“…As one of the most common fracture occurs in the vertebra (MEHTA; SEBRO, 2020;LÓPEZ et al, 2016), predicting occurrence of this injury is crucial for prevention and early treatment. Bone mineral density (BMD) is one of the reference indicators employed to diagnose osteoporosis, and is associated to an increased risk of fractures, including lumbar and hip fractures (MCCLUNG, 2005;MEHTA;SEBRO, 2020;WU et al, 2020).…”